Elaine - Yeah, I've done the Wharf to Wharf - it's also a mad house but not nearly as bad. DH and I actually sneak back to Santa Cruz early when we run it and go hang out there as it's not as crowded... Yeah, the Bay to Breakers - nothing like running with 70,000 of your best friends - some in elaborate costumes, some in nothing at all. It's definitely an experience...
As I had no idea what Asperger's Syndrome is, I looked it up. I think Martial Arts is a wonderful idea! You're such a sweet mom! One of the best benefits for him will be learning to judge distance and become better coordinated. You'll benefit too - it's a very neat experience to go through martial arts, especially with your son. You can practice together - and that's just one of the benefits. I would first start by asking friends what their experience is with different studios. You'll want one that focused on kids and the fun of the art as well as the discipline. I would go by myself and observe a couple different levels of classes (both a lower belt and a higher belt - if he likes it he will want to stick with it an earn higher belts) - what do they require of their students? Ask to speak to parents who's kids go to that studio. You want to look for a place that understands kids and knows when to push, and when to encourage - and when to step back. Speak to the head instructor or owner and find out what the philosophy of the school is - what's the focus. You'll be amazed at the different answers you get. I would also ask to take a few private lessons to start, just to give DS a feel for it. I think getting some of the punches down and some of the kicks will help when he's in a class and there's confusion - as there always is.
All studios encourage loud "kiya's" which encourage the kids to let the air out of their stomachs before a possible kick or punch as well as to intimidate their opponent. So if your DS is sensitive to sound, you may want to prepare him for that. My DD went to West Coast Tae Kwon Do and the one she went to was wonderful. The head was a former kindergarten teacher and she knew how to encourage kids. Try to go with a more accredited "art". Tae Kwon Do, Kenpo, something that is more regulated and has certain standards. You'd be surprised at what you can find out there...
Oh, I could go on and on. PM me if you need more information. I seriously think you're wonderful for doing this. We can spar after the Half! }( (joking...)